Aschool psychologist reports that the mean number of hours the students at this school sleep each night is 8 hours. the students believe the mean is not 8 hours. to find an estimate of the true mean, they select a random sample of 15 students from their school and ask how many hours each slept last night. a stemplot and boxplot of the numbers of hours are shown here. t he sample mean is 6.67 hours with a sample standard deviation of 1.88 hours. a. verify that the conditions for computing a confidence interval are met in this case. b. compute and interpret a 95% confidence interval for the mean number of hours the students at this school sleep each night.